1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor wafer, and a composite base and a composite substrate for use in that method.
2. Description of the Background Art
Manufacturing a wafer including a semiconductor crystal layer and a semiconductor layer by forming a composite substrate in which the semiconductor crystal layer is attached to a different composition base having a chemical composition different from that of the semiconductor crystal layer, growing the semiconductor layer on the semiconductor crystal layer of the composite substrate, and thereafter removing the different composition base has been proposed to efficiently manufacture a semiconductor device.
For example, Japanese Patent Laying-Open No. 2003-165798 discloses manufacturing a wafer including a single crystal sapphire substrate and a gallium nitride single crystal by attaching the single crystal sapphire substrate to a base to form a sapphire composite substrate, epitaxially growing the gallium nitride single crystal on a sapphire surface of the sapphire composite substrate, and thereafter removing the base by wet etching.